This disclosure is directed to systems and methods that provide improvements in substrate handling in image forming devices.
Printers, copiers and other types of image forming devices have become necessary productivity tools for producing and/or reproducing documents. Such image forming devices include, but are not limited to, desktop copiers, stand-alone copiers, scanners, facsimile machines, photographic copiers and developers, multi-function devices and other like systems capable of producing and/or reproducing image data from an original document, data file or the like.
As the technology expands, configurations of image forming devices are becoming increasingly more capable, and coincidentally increasingly more complex. An objective remains of allowing for greater image productivity and/or throughput while maintaining image quality. Conventionally, various types of image forming devices transport output image receiving media in linear or straight line paths, particularly between marking modules and fusing modules, in order that image forming substances deposited, for example, on output image receiving media are not disturbed prior to being ultimately fixed on the output image receiving media. Such capabilities depend on the systems themselves, for example, in the modes of operation of the systems and/or the physical complexity of the systems.
To maximize productivity in image forming devices, each component of the image forming device should be sized and/or configured in such a manner to optimize throughput of the particular component in order to attempt to maximize overall throughput capacity of the image forming device. System and device design then strikes a balance between increasing the throughput capacity of the image forming device with, for example, mediating increases in overall costs associated with the image forming device including not only increased device production costs but also increased operating costs due to, for example, increased energy costs associated with an increased throughput for which design of the device should be optimized.
Each component internal to, or associated with, image production, in an image forming device should be optimally sized for an expected maximum throughput for the overall system. Limitations in an available throughput of individual output image receiving medium substrates, upon which images are to be formed, can be analyzed with respect to each individual component. Certain of the components in the image forming device, by their characteristic nature, may tend to impede the image forming process to a greater degree than others. It is these individual components upon which a system designer may focus in attempting to optimize an output image receiving medium throughput in an image forming device.
There are many areas regarding output image receiving media substrate handling that lend themselves to optimization within image forming devices as currently configured and operated. Two examples for optimization are addressed by the systems and methods according to this disclosure as will be discussed in more detail below. Regarding image formation in, for example, electrostatic and/or xerographic image forming devices. The first component which may lend itself to optimization is the fixing and/or fusing system and individual fusers. Commonly employed to fix and/or fuse image forming substances on output image receiving media, often by a combination of heat and pressure, these modules may represent a limiting factor regarding both output image receiving media substrate throughput for, and total energy costs for operation of, a specific image forming device within which the fusing module is housed, or with which the fusing module is associated. Limitation in image output imaging receiving media throughput may arise from operating, at a controlled rate, the single fuser of a specific image forming device. Not only do fusing modules potentially limit a throughput of output image receiving media substrates, but an individual fusing module may also significantly affect specific energy costs. As such, fusing modules tend to highlight the balance required in maximizing throughput of an image forming device with other considerations with regard to specific employment. During periods of high throughput, an individual fuser may tend to generate significant heat in operation resulting in, for example, an overheat condition. Such condition may cause, for example, a thermally-based slow down and/or shutdown in the image forming device in order to preserve output image quality, and/or to prevent damage due to heat in one or more components of the image forming device. It should be recognized coincidentally that a high throughput fusing module may expend virtually the same energy regardless of an actual throughput of output image receiving media being experienced. In other words, during periods of low throughput operations, a need to maintain a high throughput fusing module heated to the same level as may be acquired for high throughput operation results in higher fusing module operating costs. These costs represents a significant portion of the energy operating costs for the image forming device, which are not optimized.
A second area to be optimized concerns configurations for output image receiving media substrate handling paths within an image forming device. Certain considerations, particularly those incumbent in transporting individual substrates upon which image forming substances have been deposited in, for example, a marking module to a fusing module in a manner that does not disturb the image forming substance deposited on the substrate prior to such substance being fixed on the substrate are considerations that tend to limit design of the substrate handling paths, particularly between marking modules and fusing modules in the image forming device. As such, physical complexity in the image forming device may also affect an available throughput. Conventionally, output image receiving media exiting the marking module, where, for example, electrostatically charged toner particles are deposited on an electrostatically charged substrate, must be very carefully handled because unfused toner is susceptible to distortion if subjected to any physical disturbance as may be induced by, for example, handling the output image receiving media in a non-linear manner.
Unfused media is a term used to describe output image receiving media to which an image forming substance such as, for example, toner has been applied in the formation of a copy of an original image, that includes text and/or graphics, and upon which the toner has not yet been fixed, generally by some form of heat and/or pressure fusing. Unfused media is particularly susceptible to image degradation based on forces due to compression and tension when such media is bent as the unfused media is being transported in a non-linear manner. Degradation of an unfused toner image, which forms the copy of the text and/or graphics, results based on disturbing the formation of the unfused toner on the unfused media. For this reason, conventionally, once the unfused media exits the marking module, the unfused media is handled in a linear manner throughout transport to a finisher such as, for example, a fusing module. Linear handling along even a portion of the image receiving media handling path in an image forming device restricts variation or optimization in an overall configuration for image forming device.